DSCC states that following the launch of the first foldable OLED devices in 2019, the market is expected to experience a very fast growth - by 2022 the market will reach 63 million units, up from 3 million in 2019 (a CAGR of 173%). In terms of revenues, the market will reach $8.9 billion by 2022 (151% CAGR).
It is a bit confusing that DSCC segments this market by device type - as foldable OLEDs will probably merge these segments together (i.e. a phone/tablet, tablet/notebook, wearable/smartphone, etc).
The first wave of foldable devices is expected in early 2019 (or maybe by the end of 2018). The first devices are expected to be Samsung's Galaxy F (smartphone/tablet), the Nubia Alpha (bracelet/smartphone) and Huawei's upcoming phone/tablet. These will probably be joined by more devices that haven't been announced yet.